Johansson, Birgitta M.

Alternative title[sv]

Mollusker, miljö och människa - ett bioarkeologiskt synsätt i Sverige

Abstract [en]

The thesis aims to examine the role and use of molluscs in Swedish prehistory, in chorological and chronological aspects. Molluscs live in the sea, fresh water and on land. The Swedish mollusc fauna contains 623 taxa: 417 marine, 85 limnic and 121 terrestrial species. Molluscs are invertebrates, have a soft body and a hard, external skeleton - the shell. Molluscs are found in all parts of Sweden, even at high altitudes, but as subfossil evidence they are restricted to calcareous bedrock, non-acid sediments and soils. The shell morphology is diversified; the cap-shaped land snails, the boat-shaped large freshwater mussels, the paddle-shaped blue mussels, the heart-shaped cockles, the fan-shaped scallops and the egg-shaped Indo-Pacific cowries and large porcelain shells. Molluscs are zoological macrofossils. The size of mollusc shells in the Swedish fauna varies from 0.5 mm up to c. 200 mm. Molluscs have environmental, social and cultural value as palaeoecological and anthropogenic indicators. A survey of 257 cases of shell bearing evidence from 104 sites in Sweden has shown that shells have been collected during excavations, but not been studied and interpreted further. A list of archaeological sites with mollusc occurrences in Sweden is provided. There are, however, several projects where the mollusc findings have not been recorded. A better understanding of the importance of molluscs among archaeologists, as well as curators in museums is suggested. An attempt is made to show ways and methods of improving the present conditions of the archaeomalacological evidence. Furthermore, an updated list of mollusc taxa and their ecological preference is provided with names in Latin, English and Swedish.

Subfossil shells can be studied from several aspects. Information from the fields of archaeology, anthropology, palaeoecology and Quaternary geology, need to be combined with recent and comprehensive information on history, ethnography, ecology and taxonomy, to fully explore the role and potential of subfossil shells in prehistory. In order to give a holistic picture on the role and importance of molluscs in archaeological contexts a multidisciplinary approach is applied.

Results show that molluscs have been used as food, personal ornaments and tools. Oysters, limpets, blue mussels and cockles played an important role as food during the Mesolithic and the Neolithic in western and southern Sweden. There is a hiatus in the use of these species until the Viking Age, when they reoccur at the site of Birka. During the early Medieval period the use of molluscs has been traced at several urban sites; Lödöse, Uppsala and Helgeandsholmen. During the Middle Neolithic on Gotland, tusk shells were used as personal ornaments. Indo-Pacific shells appear in the archaeological record during the Early Roman Iron Age. Six taxa are identified in Sweden. Scallop shells have been used as a sign of pilgrimage in Europe during the Medieval time. There are 74 scallop shells of this context found in Sweden. Future bioarchaeological mollusc studies are suggested within seven promising regions in Sweden.